Forum Discussion

drasek's avatar
drasek
Explorer
Jan 22, 2022

Trunnion Weight Distribution Spring

Hello,
I haven’t been on here for many years, more accurate about 5-8 years, lol
I have enclosed cargo ATV trailer that I’m in need of help. Trailer is Look 18 feet SE Element, GVWR 7000 lbs. tandem axle. This was towed with 2017 F250SD…no issues at all. We just got 2021 F-150 Powerboost. Truck’s towing is rated 12,700 lbs. which is nearly double from what we need. Trailer total weight when fully loaded is around 6500 lbs. I tow two Polaris side by side machines and all our gear, so the weight is distributed very evenly.
When trailer is attached to the truck, the tongue weight will push down the rear 4” and front will come up 1”. I never weighted tongue weight, but if I have to guess it would be somewhere around 700 lbs. The truck looks very level from front to back. F-150’s sits very high at rear, but is 4” too much (3” with bars)? I try to use weight distribution bars rated 800 lbs. and I’m able to get rear of the truck up only 1-1/4” and almost no changes to the front. At the moment the trailer is ¾” higher on front vs rear. I do have another set of 1200 lbs. bars, but missing chains, so I did not try that today. How much can I tilt ball towards the trailer to get more spring tension from the bars?
My question is: do you think 1200 lbs. bars would bring the truck to the level where the empty truck is or would 1K lbs. (is there 1K option) bars make better choice for me to try or should I tow with what I have? We need to tow this setup for up to a 3-4 times per year 300 miles round trips, other towing is done with class A RV. Any help I can get is greatly appreciated.
Thank you, Andrew
  • lenr's avatar
    lenr
    Explorer III
    Jan 24, 2022
    My opinion—yours may vary: X2 with BarneyS with some elaboration. Pickup trucks are designed to come down significantly in the rear under load, so a 4” drop in the rear is not generally a problem if the truck looks level. However, some of us believe that returning weight to the front axle is advantageous to good handling with the side benefit of moving weight off the rear axle. Note that if the weight distribution is set up perfectly the front bumper would move up at least 3/16th inch as the truck pivots around the front axle. So, my setup goal has been to raise the front bumper as close to 3/16th inch as possible while making sure that it is no less (which would be more weight added to the front.) As BarneyS hinted Ford often recommends a 50% difference in the height increase of the front. So, if the unhitched height is 16” and the hitched height without WD is 17”, then the goal after WD is setup would be 16.5” according to Ford while my goal has always been to get closer to 16.25”. While the hitch manufacturers suggest measuring the wheel wells to tires, it is WAY easier to measure the center of the front bumper to ground to the nearest 1/16” without moving the truck. If the trailer is not level, the only fix is to reposition the ball mount on the shank purchasing a different length shank if necessary. As the head tilt is adjusted always be sure that the chain slack is adequate for turns. Reese/Drawtite recommends as least 5 chain links. Back in the day I was able to set up our F-150 pulling a 6500 lb. trailer with a 650 lb. ATV in the bed using 800 lb. WD bars.
  • BarneyS's avatar
    BarneyS
    Explorer III
    Jan 24, 2022
    No need to spend any money. Just measure the front fender opening to ground. Then hitch up and see remeasure - note the change. Then tilt the hitch head back some, hook up again and remeasure - note the change and compare with first measurement.

    If that measurement is within 50% of the first measurement you should be good to go. Just don't get the front down lower than you started with. Don't worry about the rear as it will take care of itself and follow you wherever you go! :W

    If you would like a very detailed explanation of how to do this, click here to go to the sticky at the top of the Towing forum on how to set up a weight distribution hitch.
    Barney
  • Grit_dog's avatar
    Grit_dog
    Navigator
    Jan 23, 2022
    I’d slap on some Timbrens, Sumos, super springs or bags, take your pick.
    Hitch up and hit the road.
    But that’s me.
  • MitchF150's avatar
    MitchF150
    Explorer III
    Jan 23, 2022
    I'd just tilt the head as far as it will allow. Then hook up the #800 bars and go with it and then dial in from there.

    I'm towing #7000 and have at least #1000 TW when I run a full fresh water tank and just use an almost 20 year old set of EAZ-Lift #1000 WD setup.

    Works and tows great! I've not hit a scale, but I pack heavy and know it, so I just go with the max weights.

    Good luck! Mitch
  • Lwiddis's avatar
    Lwiddis
    Explorer II
    Jan 23, 2022
    Nothing better than accurate weights before making adjustments.
  • valhalla360's avatar
    valhalla360
    Navigator
    Jan 23, 2022
    Since you already have it, swing by the CAT scales and find out what the real weights are. That will give you a much better idea of what's really happening.

    Weigh it ready for travel, then with the bars disconnected, then the truck by itself (if you do it all at once, the re-weighs usually only cost $2-3, so total should be around $20).
  • nickthehunter's avatar
    nickthehunter
    Nomad II
    Jan 23, 2022
    You don’t want the truck back to where it is when empty. Sounds like you’re fine where your at but you may be on the light side for the tongue weight.

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